Chuck operating mechanism



N0v.1s,41941. i F..B| ANHARD ETAL y 2,263,117

CHUCK OPERAT ING MECHANISM Filed Dec. 16, 1939 5 sheets-sheet 1 WM 7m,un M4 Nov. 18, 1941. F. c. BLANCHARD mL 2,263,117

CHUCK OPERATING MECHANISM Filed Dec.` 16, 17939 5 Sheets-Shet 2 1 l I587/ T Nv. 18, 1941. F. c. BLANcH-ARD ETAL 2,263,117

CHUCK OPERATING MEGHANI SM Filed Dec. 16, 1959 5 sheets-sheets d yfm,sw. f

Nov. 18, 1941. F. c. BLANCHARD r-:T AL 2,263,117

CHUCK OPERATING MECHANISM Nov. 18,1941. F, c; BLANCHARD E-FL 2,263,117

CHUCK OPERATING MECHANISM Filed Dc. 16, 1959 5 sheets-sheet 5 ,awww-Mfw' aways.

` Patented Nov. `1,8, 1941` 2,263,117 CHUCK OPERATING MEoHANlsMFrederick C. Blanchard, Brookline, and Chester G. Brown, Newton, Mass.,assignors to Rivett Lathe & Grinder, Inc., Boston, Mass., a corporationof Massachusetts Application December 16, 1969s'eria1 No. 309,614

9 Claims.

This invention relates to lathe head-stock structures ofthe classwherein the work-piece, in the nature of a rod-like body is passedthrough a hollow head-stock spindle and is held by a holder in thenature of a collet-type chuck. The invention is more particularlyconcerned with novel chuck operating mechanism in two forms, one for adraw in chuck and the other for a push out chuck, one operating in adirection reverse to the other. The invention will best be understood byreference to the following descrip-l tion when taken in connection withthe accompanying drawings ofboth forms, while its scope will be pointedout more particularly .in the appended claims. Y

In the drawings: l p

Fig. 1 is a vertical, longitudinal sectional view of a latheV head-stockequipped with a chuck closerrof the draw in type;

Fig; 2cis an elevation ofthe saine as viewed from the left end oi Fig.1;

Fig. 3 isa lfront elevation of the hand-wheel or knob and parts securedthereto;

Fig. 4 is a sectional View on line 4-4 of Fig. 2;

Fig. 5 is a sectional view on line 5-5 of Fig. 2;

Fig. 6 is a `front elevation of a portion of the structure;

Fig. 'l is a sectional View on linel-fl of Fig. 6;

Fig. 8 is a bottom plan of the chuck operating screw and attachedsleeve;

Fig. 9 is a vertical, longitudinal section ofa .headstock structureequipped with a chuck mechanism of the pusho-ut type;

Fig. 10 is a` left-hand elevation of the handwheel or knob and' attachedparts;

Fig. 11 is a front elevation of the parts. shown in Fig. 10; Y

Fig. 12 is a sectional view on line I2-I2 of Fig,10;

Fig. 13 isa sectional view on line I3-,I3 of Fig. 10; and

Fig. 14 is a bottom plan of the chuck operating screw and attachedsleeve of the pushout type. Y

Referring to the drawings and to the embodiments of the inventionillustrated therein by way of example, and having reference at first toFig. 1, there is shown a portion of -a lathe comprising a bed I6supporting a head-stock I8 having transverse walls 26 and 22 whichsupport appropriate bearings, presently to be described, for a hollow,head-stock spindle 24. In the present example there are two suchbearings, and one of them is a one-row ball bearing while the other is atwo-row ball bearing. The rst bearing corn- (ci. 27s-.52)

prises innerand outer races 26 and 28 and an in` termediate set of balls30, while the second cornprisestwo inner races 32, two outer races 34and two `sets of balls 36. It is deemed unnecessary to describe thebearings ,in further detail. The head-stock yspindle is suit-ably drivenas by a pulley 38, herein grooved to receive V belts 46, ,and suitablysecured to the spindle.

In the draw in type, the head-stock spindle has an internal taper `l2which receives an external taper 44 on a hollow, collet chuck 46provided with longitudinal slots 48 to render the same resilientlycontractible by being drawn in (i. e. moved to the left as viewed inFig. 1) by -a hollow chuck spindle 50 whose inner or righthand end issecured to the adjacent end of the chuck as by a screw thread 52 havingsuiiicient end `clearance to allow axial adjustment ofthe chuck to suitvariations in diameter of the work. The chuck is suitably held vagainstrotation in the head-stock spindle 24 butis permitted to Amove axiallythereinas by providing the chuck with a. keyway 54 which receives a key56 attached to the head-stock spindle.

Ahand-wheel 58 is located at the outer end of the coaxial hollowspindles, and is secured to the chuck spindle 5l] (see`Fig.\5) as byscrews 66, commonly called Dutchman threaded partly into the hand wheeland partly into the chuckspindle. It will be remembered that the chuckand the chuck-spindle have screw-threaded connection wth each other andthat the chuck, although free toI move axially, is prevented by the key56 from turning in the head-stock spindle. It follows that, by graspingthe hand-wheel 58 and turning the chuck spindle 50, the chuck m-ay bedrawn in to the extent necessary to` establish preliminary engagement ofthe internal surface 62 of the chuck with the work.

To maintain the adjustment thus obtained, screws 64 threaded into thehand-wheel are then screwed inwardly into firm engagement with afriction ring 66 non-rotatably coupled to the adjacent end of thehead-,stock spindle 24 as by jaws or teeth 68 on the ring received incorrespending slots 1li in the end of the spindle. The slots are ofsuflicient length to provide a clearance beyond the ends of the jaws.Thus, the pressure of the screws 64 against the friction ring 66 forcesa shoulder 12 on the latter axially against a shoulder 14 on a secondfriction ring 16, which, as shown in Fig. 4, is suitably secured as byscrews 'I8 to the hand-wheel 58.

'Ihe binding of the friction ring 66 against'the friction ring 16, asjust described, prevents relative rotation of the two spindles 24 and 58inasmuch as the friction ring 68 is, as stated, nonrotatively coupled tothe outer end of the spindle 24. All is now in readiness for theapplication of clamping pressure of the chuck 48 against the work by apowerful inward pull of the chuck produced by the closing mechanism nowto be described.

The closing mechanism comprises an actuator, herein a ring 19 (seeFig. 1) which turns about the common axis of the described spindles, andis provided with a handle 88. This turning movement is utilized toimpart an axial movement to the chuck-spindle 50 by appropriatemechanism such as an outer sleeve 82 secured to the outer end of thehead-stock I8 as by screws 84 and having an internal, left-hand,screwthread 86, mating with an external screw-thread 88 on an innersleeve 98. It will be convenient, sometimes, to refer to the outer,internally threaded sleeve as the nut, and to refer to the inner,externally threaded sleeve as the screw. Inasmuch as the nut is heldfixed by reason of the fact that it is secured to the head-stock, itfollows that rotationpof the screw is accompanied by axial movement ofthe latter.

Assuming then that the screwfmoves outwardly, i. e. toward the left asviewed in Fig. 1, its movement is imparted to the chuck spindle 58through a suitable thrust bearing hereincomprising ball-races 92 and 94and intermediate balls 9B. The race 92 rests against a shoulder 98presented by the inner ring 98 and the race 94 rests against thefriction ring 16. On the other hand, when the screw moves inwardly, i.e., toward the right in Fig. 1, the movement is imparted to the chuckspindle 50 by reason 'of the fact that the outer face of the ring 16 isengaged by a shoulder presented by ring |82 suitably secured to thescrew 9|) as by -a thread |84 and a fastening element such as screw |08.

Returning now to the actuating ring 19, the latter is convenientlymounted to turn on and about the sleeve 82 (sometimes called the nut)and is received between a shoulder ||0 on said sleeve and a collar ||2secured to said sleeve. Hence, the actuating ring, though free to turn,is prevented from moving axially. Turning movement of the ring isconveniently communicated to the screw 90 (see Fig. '7) as by a stud ||4carried by the ring and projecting radially inward through acircumferential slot H6 in the nut 82 and into a slot I8 (see Fig. 1) ina hardened bushing |20 pressed into a correspondingly shaped opening inthe Vring |02 (see Fig. 8), and iszadditionally secured by two Dutchmenscrews It follows that partial rotation of theactuating ring 19 isaccompanied by corresponding rotation and consequent axial movement ofthe screw 90, and this axial movement is communicated to the chuckspindle.

The normal position of the actuating ring is as shown in Fig. 7 with itshandle 80 upright. Partial clockwise rotation of the ring, hereinthrough an angle of 45 from'the position shown causes the chuck to gripthe work firmly. A

' detent pin |22 has a rounded head |24 which,

under the urge of a spring |25, between the head and a bushing |28,enters either of two bushings |38 and |32 the proper angular distanceapart, in this instance 45 degrees, thus to hold the actuating ring ineither of its two positions.

As already indicated, the foregoing description is concerned with achuck of the draw-in type.

To adapt the invention to a chuck of the pushout type, certainmodifications are made and they are illustrated in Figs. 9 to 14,inclusive. Those parts which remain unchanged, or substantially so, willnot require a second description, and so far as possible bear the samereference characters as before. It is therefore convenient to proceeddirectly to the modications occasioned by the push out arrangement asdistinguished from the draw in arrangement.

In this instance, a spindle-nose |34, suitably secured to the head-stockspindle 24, has an internal taper |38 which receives an external taper|38 on a chuck |48, and the direction of taper is the reverse of thathereinbefore described. In this instance, the chuck does not havedirect, screw-threaded connection with the chuck-spindle 50, but insteadthere is an indirect connection comprising a coupling |42 threaded intothe spindle, and this coupling has a key-way |44 registering with akey-way |46 in the chuck, and both key-ways receiving a key |43 whichholds both against rotation with relation to the headstock spindle 24,Hence, turning of the chuckspindle 50 in the proper direction producesaxial outward movement of the chuck because the chuck abuts endwiseagainst the coupling |42. When, on the other hand, the chuck spindle isretracted, i. e. moved toward the left as viewed in Fig. 9, theresiliency of the chuck, tending to open the same, plus the ratherabrupt angle of the tapers |36 and |38, causes the chuck to recede andfollow the chuck spindle.

Turning now to the operating mechanism, it is evident that the thrustsshould be reversed as compared with the draw in type. This involves notonly a reversal of the threads of the screw and nut, but also a reversalof the surfaces which operate through the thrust bearing. In this form,the screws 18 (see Fig. 12) secure to the hand-wheel 58 a friction ring|50 which takes the place of the friction ring 16 of the first form andhas a shoulder |52 resting against the shoulder 12 of the friction ring86 which remains unchanged. However, in this example, the friction ring|50 is greatly elongated, as best shown in Fig. 12, and to it a collar|54 is appropriately secured as by a screw-thread |56 and by a stud |58(see Fig. 9) screwed into said collar and proiecting radially inwardinto said friction ring. The collar |54 is disposed at the right-handside of the thrust bearing as contrasted with the first form in whichthe friction ring 18 is disposed at the left-hand side of the thrustbearing.

In this second example, at the left-hand side of the thrust bearing,there is a shoulder |60 presented by a ring |62 secured as by a thread|64 and by a screw |68 to an inner sleeve |68 (best shown in Fig. 14)having a right-hand, external thread |18 which mates with an internalthread |12 (see Fig. 9) formed in an outer sleeve |14. It will beconvenient in this case, also, to refer to the inner, threaded sleeve|68 as the screw and to refer to the outer, threaded sleeve |14 as thenut, as in the first example.

It should now be evident that rocking of the actuating ring 19 of thesecond example by movement of the handle 88 toward the operator actsthrough the screw |88 and nut |14 to push the chuck |40 outwardly, i.e., to the right as viewed in Fig. 9, thereby causing contraction of thechuck and consequent gripping of the work, and conversely that rockingof the handle rearwardly causes the chuck to relax and to release thework.

In each example, the required movement of the operating handle isslight, and the movement is smooth and powerful.

Having thus' described two embodiments of thev invention but withoutlimitingl ourselves thereto, what we claim and desire, by LettersPatent, to secure is:

1. In a mechanism for operating a chuck oi the collet type wherein thework to be grasped by the chuck is disposed axially within a hollowspindle by which the work is rotated, lthe combination of inner andouter members which are relatively rotatable about the chuck axis, meansconnecting said members to each other to utilize their relative rotationto cause their relative axial movement, an actuator which turns onvandabout said outer member about said axis, means extending from saidactuator through said outer member and connecting said actuator to saidinner member, a rotatable and axially movable chuck spindle, and meansto cause axial movement of said inner member to be transmitted to saidchuck spindle.`

2. The combination with a machine tool head and its spindle, of a hollowchuck to be rotated by said spindle, inner and outer, concentric,relatively rotatable members coaxial with said spindle and said chuck,one of said members being secured to said head, means connecting saidmembers to utilize rotation of the other member to cause its axialmovement, an actuating ring coaxial with said spindle, `means to causeturning of said ring to be accompanied by turning of said other member,and means to utilize said axial movement to cause said chuck to grip thework.

3. The combination of a machine tool head and its spindle, of a hollowchuck to be rotated by said spindle, inner and outer, concentric,relatively rotatable members coaxial with said spindle and said chuck,one of said members being secured to said head, means connecting saidmembers to utilize rotation of the other member tocause its axialmovement, an actuating ring about and coaxial with the member which issecured to said head, means connecting said ring to the othermember tocause turning of said ring to be accompanied by turning of said othermember, and means to utilize said axial movement to cause said chuck togrip the I chuck within and keyed to said spindle and having an externaltaper engaging said internal taper, a second spindle mounted within saidrst spindle to move axially and rotatably and having screw-threadedconnection with said chuck, a hand-wheel secured to the outer end ofsaid second spindle, an outer sleeve secured to the outer end of saidhead and having an internal screw-thread, a circumferentially extendingslot and an outwardly-facing shoulder, a collar secured to said sleeveand having an inwardly-facing shoulder, an actuating ring disposedbetween said shoulders and mounted to turn on and about said sleeve, ahandle to swing said ring about said sleeve, a stud carried by said ringand projecting radially inward through said slot, an axially androtatably movable, inner sleeve having an external screw-thread matingwith said internal screw-thread and connected l with said stud to beturned in unison with said actuating ring, a thrust bearing about saidrst spindle, and means to utilize axial movement i which the chuck isrotated, the combination of* of said inner sleevel to act through saidthrust bearing to movesaid chuck spindle andj said chuck axially. i

5. In a machine tool, the combination of a head, a rst spindle rotatablymounted therein and having an internal taper, a contractible chuckwithin and keyed to said spindle and having an external taper engagingsaid internal taper, a second spindle mounted within said iirst spindleto move axially and rotatably 'and having screw-threaded connection withsaid chuck, a hand-wheel secured to the outer end of said secondspindle, alfriction ring non-rotatablycoupled to said first spindle,screw means carried by said hand-wheel to exert a pressure on saidclamping ring, an outer sleeve secured to the outer end of said head andhaving an internal screw-thread, a circumferentially extending slot andan outwardly-facing shoulder, a collar secured to said sleeve and havingan inwardly-facingvshoulder, an actuating ring disposed between saidshoulders and mounted to turn on and about said sleeve, a handle toswing said ring about said sleeve, a stud carried by said ring andprojecting radially inward through said slot, an axially and rotatablymovable, inner sleeve having an external screw-thread mating with saidinternal screw-thread and connected with said stud to be turned11i-unison with said actuating ring, a thrust bearing about said firstspindle, and means to utilize axial movement of said inner sleeve to actthrough said thrust bearing to move said second spindle and said chuckaxially. y

6. In a' mechanism for operating a chuck of the type wherein the work tobe held by the chuck is passed through a hollow spindle by two memberswhich are relatively rotatable about the spindle axis, means connectingsaid memi y bers to each other to utilize their relative rotation tocause their relative axial movement, means to hold one of said membersiixed against rotation, an actuator coaxial with` and turning about thefixed member and connected with the other member to` rotate the latterabout the chuck axis, actuator limiting means to limit and denne theangular movement of said actuator about said axis, said limiting meansincluding a part carried by said actuator, and axedparthaving aformation which cooperates with the rstnamed part, and means to utilizerelative axial movement of said members to operate the chuck, thelast-mentioned means including a hollow chuck spindle operating throughthe first-mentioned spindle.

7. In a mechanism for operating a chuck of the type wherein the work tobe held by the chuck is passed through a hollow spindle by which thechuck is rotated, the combination of two members which are relativelyrotatable about the spindle axis, means connecting said members to eachother to utilize their relative rotation to cause their relative axialmovement, means to hold one of said members xed against rotation, anactuator coaxial with and turning about the fixed member and connectedwith the other member to rotate the latter about the chuck axis,actuator limiting means to limit and denne angular movement of saidactuator about said axis, said limiting means including a fixed parthaving a slot, and a movable part which moves angularly to and fro insaid slot, and means to utilize relative axial movement of said membersto operate the chuck, the last-mentioned means including a hollowchuck-spindle operating through the first-mentioned spindle.

8. In a machine tool, the combination of a head, a spindle and a chuckhaving cooperating tapers to utilize their relative axial movement tooperate said chuck, and mechanism to move said chuck axially, saidmechanism including two members which are supported by said headindependently of said spindle and turn one with relation to the otherabout the spindle axis, and means connecting said members to each otherto utilize their relative rotation to move said chuck axially, one ofsaid members being attached to said head and thereby held xecl againstrotation.

9. In a machine tool, the combination of a head, a spindle and a chuckhaving cooperating tapers to utilize their relative axial movement tooperate said chuck, and mechanism to move said chuck axially, saidmechanism including two members one of which is secured to said head andthe other of which is rotatable about the spindle axis, means connectingsaid members to utilize rotation of one to cause axial movement of thesame, an actuator supported by said head independently of said spindleand arranged to turn the rotatable member, and means to transmit axialmovement of the rotatable member to said chuck.

FREDERICK C. BLANCHARD. CHESTER G. BROWN.

